Metal ion homeostasis is critical to the survival of all cells. Regulation of nickel concentrations in Escherichia coli is mediated by the NikR repressor via nickel-induced transcriptional repression of the nickel ABC-type transporter, NikABCDE. Here, we report two crystal structures of nickel-activated E. coli NikR, the isolated repressor at 2.1 A resolution and in a complex with its operator DNA sequence from the nik promoter at 3.1 A resolution. Along with the previously published structure of apo-NikR, these structures allow us to evaluate functional proposals for how metal ions activate NikR, delineate the drastic conformational changes required for operator recognition, and describe the formation of a second metal-binding site in the presence of DNA. They also provide a rare set of structural views of a ligand-responsive transcription factor in the unbound, ligand-induced, and DNA-bound states, establishing a model system for the study of ligand-mediated effects on transcription factor function.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1564233 | PMC |
| http://dx.doi.org/10.1073/pnas.0606247103 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Zinc Combined with Metformin Corrects Zinc Homeostasis and Improves Steroid Synthesis and Semen Quality in Male Type 2 Diabetic Mice by Activating PI3K/AKT/mTOR Pathway.
Biol Trace Elem Res
January 2025
Hebei Key Laboratory of Reproductive Medicine, Hebei Reproductive Health Hospital, Shijiazhuang 050071, Hebei, China.
Male infertility is a common complication of diabetes. Diabetes leads to the decrease of zinc (Zn) content, which is a necessary trace element to maintain the normal structure and function of reproductive organs and spermatogenesis. The purpose of this study was to investigate the effect of metformin combined with zinc on testis and sperm in diabetic mice.
View Article and Find Full Text PDFUnlocking the Key to Photocatalytic Hydrogen Production Using Electronic Mediators for Z-Scheme Water Splitting.
J Am Chem Soc
January 2025
State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.
A prevalent challenge in particulate photocatalytic water splitting lies in the fact that while numerous photocatalysts exhibit outstanding hydrogen evolution reaction (HER) activity in organic sacrificial reagents, their performance diminishes markedly in a Z-scheme water splitting system using electronic mediators. This underlying reason remains undefined, posing a long-standing issue in photocatalytic water splitting. Herein, we unveiled that the primary reason for the decreased HER activity in electronic mediators is due to the strong adsorption of shuttle ions on cocatalyst surfaces, which inhibits the initial proton reduction and results in a severe backward reaction of the oxidized shuttle ions.
View Article and Find Full Text PDFFormation of Nanowindow between Graphene Oxide and Carbon Nanohorn Assisted by Metal Ions.
Langmuir
January 2025
Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan.
This study presents a novel nanostructured material formed by inserting oxidized carbon nanohorns (CNHox) between layered graphene oxide (GO) nanosheets using metal ions (M) from nitrate as intermediates. The resulting GO-CNHox-M structure effectively mitigated interlayer aggregation of the GO nanosheets. This insertion strategy promoted the formation of nanowindows on the surface of the GO sheets and larger mesopores between the GO nanosheets, improving material porosity.
View Article and Find Full Text PDFLigand engineering regulation toward Zn ions and Zn substrate for all-climate Zn metal batteries.
Angew Chem Int Ed Engl
January 2025
Shandong university, School of Chemistry and Chemical Engineering, No 27, Shandananlu,, 250100, Jinan, CHINA.
The regulation of artificial interphase for advanced Zn anode is an effective solution to achieve superior electrochemical performance for aqueous batteries. However, the deployment of atomically precise architectures and ligand engineering to achieve functionalization-oriented regulatory screening is lacking, which is hindered by higher requirements for synthetic chemistry and structural chemistry. Herein, we have first performed ligand engineering which selected zinc ion trapping ligands (-CH3) based on the coordination effect, and zinc substrate binding ligands (-N=N-xC6H5) based on the electrostatic interaction.
View Article and Find Full Text PDFElectrosynthesis of Silane-Modified Magnetic Nanoparticles for Efficient Lead Ion Removal.
ChemSusChem
January 2025
Swinburne University of Technology - Hawthorn Campus: Swinburne University of Technology, Chemistry and Biotechnology, AUSTRALIA.
The removal of heavy metal ions, such as lead (Pb2+), from aqueous systems is critical due to their high toxicity and bioaccumulation in living organisms. This study presents a straightforward approach for the synthesis and surface modification of iron oxide nanoparticles (IONPs) for the magnetic removal of Pb2+ ions. IONPs were produced via electrosynthesis at varying voltages (10-40 V), with optimal magnetic properties achieved at 40 V resulting in highly crystalline and magnetic IONPs in the gamma-maghemite (γ-Fe2O3) phase.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!